Princeton 2012/Barron 4th ed.
AP Practice Problems
Unit 3 – Periodic Table
Multiple Choice (no calculator)
For questions 1-3, one or more of the
following responses will apply; each
response may be used more than once or not
at all in these questions.
(A)
(B)
(C)
(D)
(E)
Hg
Si
Cu
Zn
Ag
1. This element is commonly used in
the manufacture of semiconductors.
(P3.5)
2. This element is a liquid at room
temperature. (P3.6)
3. After oxygen, this is by far the most
common element in the earth’s crust.
(P3.7)
4. Which of the following statements is
true regarding sodium and chlorine?
(P3.9)
a. Sodium has a greater
electronegativity and a
larger first ionization
energy.
b. Sodium has a larger first
ionization energy and a
larger atomic radius.
c. Chlorine has a larger atomic
radius and a greater
electronegativity.
d. Chlorine has a greater
electronegativity and a
larger first ionization
energy.
5. Which of the following is true of the
alkali metal elements? (P3.13)
a. They usually take the +2
oxidation state.
b. They have oxides that act as
acid anhydrides.
c. They form covalent bonds
with oxygen.
d. They are generally found in
nature in compounds.
e. They have relatively large
first ionization energies.
6. Which of the following has the
smallest ionic radius? (P3.15)
a.
b.
c.
d.
e.
O2FNa+
Mg2+
Al3+
7. The ionization energies for an
element are listed in the table below.
(P3.19)
First Second Third Fourth Fifth
8eV 15eV 80eV 109eV 141eV
Based on the ionization energy table,
the element is most likely to be
a.
b.
c.
d.
e.
sodium.
magnesium.
aluminum.
silicon.
phosphorous.
Princeton 2012/Barron 4th ed.
8. A researcher listed the first five
ionization energies for a silicon atom
in order from first to fifth. Which of
the following lists corresponds to the
ionization energies for silicon?
(P3.20)
a. 780 kJ, 13,675 kJ, 14,110 kJ,
15,650 kJ, 16,100 kJ
b. 780 kJ, 1,575 kJ, 14,110 kJ,
15,650 kJ, 16,100 kJ
c. 780 kJ, 1,575 kJ, 3,220 kJ,
15,650 kJ, 16,100 kJ
d. 780 kJ, 1,575 kJ, 3,220 kJ,
4,350 kJ, 16,100 kJ
e. 780 kJ, 1,575 kJ, 3,220 kJ,
4,350 kJ, 5,340 kJ
For questions 9-13, one or more of the
following responses will apply; each
response may be used more than once or not
at all in these questions.
(A)
(B)
(C)
(D)
(E)
sodium
strontium
uranium
bromine
bismuth
9. Trends in the periodic table show
that elements become more metallic
in character from the top of a group
to the bottom. Which of these is an
element whose properties are
opposite those of the element at the
top of its group? (B2.1)
10. The halogen in this group is (B2.2)
11. The element that contains 38 protons
is (B2.3)
12. There are only two liquid elements at
room temperature and atmospheric
pressure. One of these is (B2.4)
13. The atom with the largest radius is
(B2.5)
14. The differentiating electrons for
transition elements are (B2.6)
a.
b.
c.
d.
e.
d electrons
s electrons
p electrons
f electrons
valence electrons
15. The best way to estimate the boiling
point of Pd is to (B2.7)
a. average the boiling points of
Rh and Ag
b. average the boiling points of
Ni and Pt
c. average the boiling points of
Ir and Cu
d. average the boiling points of
Co and Au
e. None of the above will work.
16. In which of the following pairs is the
first element expected to have the
higher electronegativity than the
second? (B2.8)
a.
b.
c.
d.
e.
O, P
Cs, Rb
I, Br
Al, P
Sb, As
17. A solid element has two valence
electrons. That element must be
(B2.10)
a.
b.
c.
d.
e.
a halogen
a noble gas
a radioactive element
an alkali metal
an alkaline earth metal
Princeton 2012/Barron 4th ed.
18. Which of the following is expected
to have the largest third ionization
energy? (B2.13)
a.
b.
c.
d.
e.
Be
B
C
N
Al
19. Which pair of elements is expected
to have the most similar properties?
(B2.14)
a.
b.
c.
d.
e.
Potassium and lithium
Sulfur and phosphorous
Silicon and carbon
Strontium and barium
Fluorine and iodine
20. Most elements on the periodic table
are (B2.15)
a.
b.
c.
d.
e.
nonmetals
liquids
gases
metals
metalloids
21. The chemical symbol for antimony is
(B2.18)
a.
b.
c.
d.
e.
Sn
Ti
Sb
K
At
22. In which pair of elements is the
larger atom listed first? (B2.19)
a.
b.
c.
d.
e.
K, Ca
Na, K
Cl, S
Mg, Na
O, N
23. Which of the following is LEAST
likely to be a metalloid? (B2.20)
a.
b.
c.
d.
e.
As
Hg
Ge
Si
Sb
Princeton 2012/Barron 4th ed.
Essays
1. Explain each of the following in terms of atomic and molecular structures. (P3.1)
a. The first ionization energy for magnesium is greater than the first ionization
energy for calcium.
b. The first and second ionization energies for calcium are comparable, but the
third ionization energy is much greater.
c. Solid sodium conducts electricity, but solid sodium chloride does not.
d. The first ionization energy for aluminum is lower than the first ionization
energy for magnesium.
2. Use your knowledge of the periodic table to answer the following questions. (P3.3)
a. Explain the trend in electronegativity from P to S to Cl.
b. Explain the trend in electronegativity from Cl to Br to I.
c. Explain the trend in atomic radius from Li to Na to K.
d. Explain the trend in atomic radius from Al to Mg to Na.
Princeton 2012/Barron 4th ed.
Answer Key – Unit 3: Periodic Table
Multiple Choice
1. B
2. A
3. B
4. D
5.
6.
7.
8.
D
E
B
D
9. E
10. D
11. B
12. D
13. C
14. A
15. B
16. A
17. E
18. A
19. D
20. D
21. C
22. A
23. B
Essays
1. (a) Ionization energy is the energy required to remove an electron from an atom. The
outermost electron in Ca is at the 4s energy level. The outermost electron in Mg is at the
3s level. The outermost electron in Ca is at the higher energy level and is more shielded
from the nucleus making it easier to remove.
(b) Calcium has two electrons in its outer shell. The second ionization energy will be
larger than the first but still comparable because both electrons are being removed from
the same energy level. The third electron is much more difficult to remove because it is
being removed from a lower energy level, so it will have a much higher ionization energy
than the other two.
(c) Solid sodium exhibits metallic bonding, in which the positively charged sodium ions
are held together by a sea of mobile, delocalized electrons. These electrons move freely
from nucleus to nucleus, making solid sodium a good conductor.
Sodium chloride exhibits metallic bonding, in which positively charged sodium ions and
negatively charged chlorine ions hold fixed places in a crystal lattice. The electrons are
localized around particular nuclei and are not free to move about the lattice. This makes
solid sodium chloride a bad conductor of electricity.
(d) The valence electron to be removed from magnesium is located in the completed 3s
subshell, while the electron to be removed from aluminum is the lone electron in the 3p
subshell. It is easier to remove the electron from the higher-energy 3p subshell than from
the loer energy (completed) 3s subshell, so the first ionization energy is lower for
aluminum.
2. (a) Electronegativity is the pull of the nucleus of one atom on the electrons of other
atoms; it increases from P to S to Cl because nuclear charge increases. This is because as
you move from left to right across the periodic table, atomic radii decrease in size.
Increasing nuclear charge means that Cl has the most positively charged nucleus of the
three and will exert the greatest pull on the electrons of other atoms.
(b) Electronegativity is the pull of the nucleus of one atom on the electrons of other
atoms; it decreases from Cl to Br to I because electron shells are added. The added
electron shells shield the nucleus, causing it to have less of an effect on the electrons of
other atoms. Therefore, iodine will exert the least pull on the electrons of other atoms.
Princeton 2012/Barron 4th ed.
(c) Atomic radius increases from Li to Na to K because electrons are being added in
higher energy levels, which are farther away from the nucleus; therefore, the K atom is
the largest of the three.
(d) Atomic radius increases from Al to Mg to Na because protons are being removed
from the nucleus while the energy levels of the valence electrons remain unchanged. If
there are fewer positive charges in the nucleus, the electrons of Na will be less attracted
to the nucleus and remain farther away.